[Python] Handle type hints having ","
[Python] Handle type hints having ","

Enhance argument parsing for type hints having ","
, such as "arg: Tuple[int, int]".

phatograph/vim-snippets,craigp/vim-snippets,adam-e-trepanier/vim-snippets,honza/vim-snippets,kevinkirkup/vim-snippets,kevinkirkup/vim-snippets,honza/vim-snippets,adam-e-trepanier/vim-snippets,craigp/vim-snippets,phatograph/vim-snippets